Growth and development of representatives of the genus Rosa L. in the Stavropol Botanical Garden

Abstract

Relevance. To identify the features of the growth and development of species of roses of different geographical origin, to establish the biological minimum temperatures necessary for the beginning of flowering of representatives of the genus Rosa L., to study the morphological indicators of fruits.Methodology. The research material was 12 wild roses belonging to 4 sections: Canina Crep, Cinnamomeae DC, Luteae Crep, Pimpinellifoliae DC. The research was carried out using the methods of the Main Botanical Garden, floral and geographical analyses — according to Hrzhanovsky. A caliper was used to measure the length and diameter of 10 fruits. For the analysis of statistical data, the MS Excel table processor and the integrated MATLAB mathematical package were used.Results. The article presents the results of a study of species of roses in the Stavropol Botanical Garden of various geographical origin. The study involved 12 species belonging to 4 sections. The features of growth and development of plants in new soil and climatic conditions are revealed. The dates of the beginning of the main phenological phases andtheir duration have been established: spring regrowth of shoots, budding, beginning and end of flowering, fruiting. In the studied species of roses, the growing season begins in the first — second decade of March, flowering occurs in late May — early June, the fruits ripen in August — September. The dependence of the timing of the beginning of flowering in the studied roses on the dynamics of the accumulated average daily air temperatures and the sum of effective temperatures above 5 °C was revealed. Mathematically, it was proved that the lower limit of the air temperature required for the beginning of flowering of species of roses is +16 °C, when the sum of the average daily temperature air St° = 1007.75–1069.48 °С and St эф > 5 °С = 530.75–594.75 °С are accumulated. Early flowering species of roses include Rosa foetida Herrm., R. pendulina L., R. pimpinellifolia L., late flowering — R. caudata Baker and R. corymbifera Borkh. The shortest flowering period is in R. caudata Baker, R. jacutica Juz. and R. kamtschatica Vent. Representatives of those types mostly bloom once. Their flowers are formed on biennial and more mature shoots. The flowering period is 13–23 days. Rosa rugosa Thunb. blooms again, its flowering period is extended and long — from 40 to 48 days. All species of roses form fruits. The longest fruits are in R. pendulina L., R. caudata Baker, R. rugosa Thunb., R. corymbifera Borkh. and R. canina L., and large ones — in R. rugosa Thunb., R. marretii Lev. and R. roxburghi Tratt.